The efficiencies and performance of gas turbine cycles are highly dependent on parameters such as the turbine inlet temperature (TIT), compressor inlet temperature (T1), and pressure ratio (Rc). This study analyzed the effects of these parameters on the energy efficiency, exergy efficiency, and specific fuel consumption (SFC) of a simple gas turbine cycle. The analysis found that increasing the TIT leads to higher efficiencies and lower SFC, while increasing the To or Rc results in lower efficiencies and higher SFC. For a TIT of 1400 ℃, T1 of 20 ℃, and Rc of 8, the energy and exergy efficiencies were 32.75% and 30.9%, respectively, with an SFC of 187.9 g/kWh. However, for a TIT of 900 ℃, T1 of 30 ℃, and Rc of 30, the energy and exergy efficiencies dropped to 13.18% and 12.44%, respectively, while the SFC increased to 570.3 g/kWh. The results show that there are optimal combinations of TIT, To, and Rc that maximize performance for a given application. Designers must consider trade-offs between efficiency, emissions, cost, and other factors to optimize gas turbine cycles. Overall, this study provides data and insights to improve the design and operation of simple gas turbine cycles.

Building cooling load depends on heat gains from the outside environment. Appropriate orientation and masonry materials play vital roles in the reduction of overall thermal loads buildings. A net-zero energy building performance has been analyzed in order to ascertain the optimum orientation and wall material properties, under the climatic conditions of Owerri, Nigeria. Standard cooling load estimation techniques were employed for the determination of the diurnal interior load variations in a building incorporating renewable energy as the major energy source, and compared with the situation in a conventionally powered building. The results show a 19.28% reduction in the building’s cooling load when brick masonry was used for the wall construction. It was observed that a higher heat gain occurred when the building faced the East-West direction than when it was oriented in the North-South direction. Significant diurnal cooling loads variation as a result of radiation through the windows was also observed, with the east facing windows contributing significantly higher loads during the morning hours while the west facing windows contributed higher amounts in the evening. The economic analysis of the net-zero energy building showed an 11.63% reduction in energy cost compared to the conventional building, with a 7-year payback period for the use of Solar PV systems. Therefore, the concept of net-zero energy building will not only help in energy conservation, but also in cost savings, and the reduction of carbon footprint in the built environment.

This research introduces a novel framework integrating stochastic finite element analysis (FEA) with advanced circular statistical methods to optimize heat pump efficiency under material uncertainties. The proposed methodologies and optimization focus on balancing the mean efficiency and variability by adjusting the concentration parameter of the Von Mises distribution, which models directional variability in thermal conductivity. The study highlights the superiority of the Von Mises distribution in achieving more consistent and efficient thermal performance compared to the uniform distribution. We also conducted a sensitivity analysis of the parameters for further insights. The results show that optimal tuning of the concentration parameter can significantly reduce efficiency variability while maintaining a mean efficiency above the desired threshold. This demonstrates the importance of considering both stochastic effects and directional consistency in thermal systems, providing robust and reliable design strategies.

Traditional building heating warms entire rooms, often leaving some dissatisfied with uneven warmth. Recently, the personalized heating system has addressed this by providing targeted warmth, enhancing comfort and satisfaction. The personalized heating system in this study is a new enclosed personalized heating system consisting of a semi-enclosed heating box and an insulated chair covered with a thick blanket. The study compares the heating effects of semi-enclosed and enclosed localized heating systems on the body and examined changes in subjects’ thermal sensations. Due to the lower heat loss of the enclosed personalized heating system compared to the semi-enclosed version, it created thermal micro-environments with higher ambient temperatures. The maximum air temperature increase within the enclosed system was twice that of the semi-enclosed system, with the heating film surface temperature rising by up to 6.87 ℃. Additionally, the temperature of the skin could increase by as much as 6.19 ℃, allowing individuals to maintain thermal neutrality even when the room temperature dropped as low as 8 ℃. A two-factor repeated measures analysis of variance revealed differences in temperature sensitivity across various body regions, with the thighs showing a notably higher response under high-power heating conditions. The corrective energy and power requirements of the enclosed personalized heating system also made it more energy-efficient than other personalized heating systems, with a minimum value reaching 6.07 W/K.

Segregating the scavenging processes from the lubrication methodology is a very effective way of improving two-stroke cycle engine durability. The application of stepped or twin diameter pistons is one such method that has repeatedly shown significantly greater durability over comparable crankcase scavenged engines together with an ability to operate on neat fuel without any added oil. This research study presents the initial results observed from a gasoline/indolene fuelled stepped piston engine ultimately intended for Hybrid Electric Vehicle and/or Range Extender Electric Vehicle application using hydrogen fuelling. Hydrogen fuelling offers the potential to significantly reduce emissions, with near zero emission operation possible, and overcoming the serious issues of range anxiety in modern transport solutions. The low environmental impact is discussed along with results from 1-d Computational Fluid Dynamic modelling. The engine type is a low-cost solution countering the financial challenges of powertrain duplication evident with Hybrid Electric and Range Extender Electric Vehicles.

The need for global energy conservation has become more urgent because of the negative effects of excessive energy use, such as higher fuel consumption, greater environmental pollution, and depletion of the ozone layer. There has been a significant increase in the demand for central and high-capacity household air conditioning systems in Muscat in recent years. The need for this is influenced by factors such as arid climate, increasing temperatures, air pollution, and population increase. As a result, there has been a significant increase in electricity use, putting a strain on power resources. To tackle this difficulty, the incorporation of solar collectors as supplementary thermal compressors in air conditioning systems offers a chance to utilise renewable energy sources. The objective of this hybrid technique is to enhance the effectiveness of cooling systems, hence minimising the need for electricity and lowering the release of environmental pollutants.